Open Error Path

Safe IO code should handle the path where input is not available.

open_error_path.pl

use strict;
use warnings;

my $available = ;
my $content = "ready\n";
my $message;

if ($available) {
    $message = $content;
    chomp $message;
} else {
    $message = "not available";
}

print "available=$available\n";
print "message=$message\n";

use strict;
use warnings;

my $available = ;
my $content = "ready\n";
my $message;

if ($available) {
    $message = $content;
    chomp $message;
} else {
    $message = "not available";
}

print "available=$available\n";
print "message=$message\n";

error path An error path records what happened when the normal path cannot continue.